Gentoo: X.Org X server Multiple vulnerabilities
Posted by Benjamin D. Thomas   
Gentoo Multiple vulnerabilities have been discovered in the X.Org X server, possibly allowing for the remote execution of arbitrary code with root privileges.
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Gentoo Linux Security Advisory                           GLSA 200806-07
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                                             http://security.gentoo.org/
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   Severity: High
      Title: X.Org X server: Multiple vulnerabilities
       Date: June 19, 2008
       Bugs: #225419
         ID: 200806-07

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Synopsis
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Multiple vulnerabilities have been discovered in the X.Org X server,
possibly allowing for the remote execution of arbitrary code with root
privileges.

Background
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The X Window System is a graphical windowing system based on a
client/server model.

Affected packages
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     -------------------------------------------------------------------
      Package               /   Vulnerable   /               Unaffected
     -------------------------------------------------------------------
   1  x11-base/xorg-server     < 1.3.0.0-r6               >=3D 1.3.0.0-r6=


Description
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Regenrecht reported multiple vulnerabilities in various X server
extensions via iDefense:

* The SProcSecurityGenerateAuthorization() and
   SProcRecordCreateContext() functions of the RECORD and Security
   extensions are lacking proper parameter validation (CVE-2008-1377).

* An integer overflow is possible in the function ShmPutImage() of
   the MIT-SHM extension (CVE-2008-1379).

* The RENDER extension contains several possible integer overflows in
   the AllocateGlyph() function (CVE-2008-2360) which could possibly
   lead to a heap-based buffer overflow. Further possible integer
   overflows have been found in the ProcRenderCreateCursor() function
   (CVE-2008-2361) as well as in the SProcRenderCreateLinearGradient(),
   SProcRenderCreateRadialGradient() and
   SProcRenderCreateConicalGradient() functions (CVE-2008-2362).

Impact
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Exploitation of these vulnerabilities could possibly lead to the remote
execution of arbitrary code with root privileges, if the server is
running as root, which is the default. It is also possible to crash the
server by making use of these vulnerabilities.

Workaround
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It is possible to avoid these vulnerabilities by disabling the affected
server extensions. Therefore edit the configuration file
(/etc/X11/xorg.conf) to contain the following in the appropriate
places:

       Section "Extensions"
     	Option "MIT-SHM" "disable"
     	Option "RENDER" "disable"
     	Option "SECURITY" "disable"
       EndSection

       Section "Module"
        Disable "record"
       EndSection

Resolution
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All X.org X Server users should upgrade to the latest version:

     # emerge --sync
     # emerge --ask --oneshot --verbose ">=3Dx11-base/xorg-server-1.3.0.0=
-r6"

References
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   [ 1 ] CVE-2008-1377
         http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2008-1377
   [ 2 ] CVE-2008-1379
         http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2008-1379
   [ 3 ] CVE-2008-2360
         http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2008-2360
   [ 4 ] CVE-2008-2361
         http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2008-2361
   [ 5 ] CVE-2008-2362
         http://cve.mitre.org/cgi-bin/cvename.cgi?name=3DCVE-2008-2362

Availability
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This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

   http://security.gentoo.org/glsa/glsa-200806-07.xml

Concerns?
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Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
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Copyright 2008 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.5